Certain compounds in coffee may have neuroprotective effects that could potentially reduce the risk for developing Alzheimer disease (AD) or Parkinson disease (PD), according to research out of the Krembil Brain Institute in Toronto, ON, Canada.

Specifically, the authors found that the compounds known as phenylindanes inhibited the aggregation of the amyloidgenic proteins beta-amyloid and tau, 2 proteins associated with AD and PD. In their study, the researchers observed that compared with light roast coffee, dark roast had higher levels of phenylindanes, and could potentially lead to a greater protective effect. “The caffeinated and decaffeinated dark roast both had identical potencies in our initial experimental tests,” said Dr Ross Mancini, a research fellow in medicinal chemistry. “So we observed early on that its protective effect could not be due to caffeine.”

While the authors acknowledge that a combination of factors may contribute to the neuroprotective effect associated with coffee consumption, they believe the identification of phenylindane as a dual-inhibitor of both beta-amyloid and tau is “noteworthy.”

“It’s the first time anybody’s investigated how phenylindanes interact with the proteins that are responsible for Alzheimer’s and Parkinson’s,” said Dr Mancini. “The next step would be to investigate how beneficial these compounds are, and whether they have the ability to enter the bloodstream, or cross the blood-brain barrier.”